#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>

using namespace std;

int takeAttendance(vector<int>& records) {
    int left = 0, right = records.size() - 1;

    while (left < right)
    {
        int mid = left + (right - left) / 2;
        if (records[mid] == mid)
            left = mid + 1;
        else
            right = mid;
    }

    return left == records[left] ? left + 1 : left;
}

int main()
{

	return 0;
}